Human Dimensions of Global Warming

Human Consequences of Climate Change

images of people affected by flooding. Boy on raft with goats, people moving goods through water, woman in neck-deep water
These images show some of the impacts of flooding in Bangladesh, which is a major concern associated with climate change for the country.

The human consequences of climate change also fall into two categories: impacts and responses. The impacts of climate change denote a positive or negative change in a natural or human system caused by its exposure to climate change. A positive impact on an agricultural system, for example, would be increased yields, but a negative impact would be decreased yields. The severity of the impacts is determined by the vulnerability of that system; that is, how badly the system could be hurt by its exposure to climate change. All things being equal, a crop that is little affected by rising temperature is less vulnerable than one that is greatly affected by the same temperature increase. A farmer who has the knowledge or resources to change his farming practices to match the new temperature regime is less vulnerable than a farmer who lacks sufficient knowledge or resources to adjust.

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Figure 1.4: This graphic shows one potential mitigation option: the storage of carbon dioxide in geological voids.
Click link to expand for a text description of Figure 1.4
One mitigation technique involves injecting CO2 into underground geological voids for storage. Some storage options include pumping CO2 into deplete oil and gas reservoirs, into unmineable coal seams, deep saline formations, or other basalt, oil shales, etc. cavities. Pumping CO2 into coal beds or oil and gas reservoirs can help increase % recovery while storing the CO2.
Credit: IPCC. (2005). Carbon dioxide capture and storage: Summary for policymakers. p. 6.

Humans can respond to climate change impacts in two ways. First, they can address the causes of climate change through mitigation. Mitigation involves actions that prevent, limit, delay, or slow the rate of climate change. Mitigation can involve direct interventions in the natural environment, direct interventions in the proximate causes, or indirect interventions through the driving forces. An example of mitigation would be government policies aimed at reducing the number of cars on the road and, consequently, the carbon dioxide emissions from tail pipes. As noted above, upcoming lessons will delve more deeply into the topic of mitigation.

A farmer in a field using organic fertilizer
An example of climate change adaptation in developing countries; that is, efficient use of waste water in domestic gardens.
Credit: Retrieved August 10, 2011 from

Humans can also reduce vulnerability to climate change impacts through adaptation. Adaptation involves actions taken in response to climate change that enhance compatibility with the new environment by reducing vulnerability and building resilience. For instance, coastal communities can take many actions to address the impacts of sea level rise: build sea walls, increase natural vegetation to reduce erosion, or retreat from the coast by promoting inland development and preventing further coastline development. Lesson 3 focuses on climate impacts and adaptation, with special attention to vulnerability and resilience. Lessons 7 through 10 address climate impacts and adaptation in four critical human systems––water resources, coastal zones, human health, and cities.